The CD4011 clock is sorted both sides are running at a visible rate suitable for clocking sequencer type stuff. At least for testing anyway

First iteration of the breadboarded sequencer was wired in the the wires were ripped out when it didn't work . I'm not worried. Following logic paths is a bit of an art I think and I'm well out of practice!

To this end I am GIMPing a map as it were. I have the schematic on one side of an image and on the other I have plan view representations of the chips I'm using. For the 4081 and 4001 this also includes the symbols wired to pins for easier cross reference.

I have also colour coded each logic gate in the schematic and then colour coded each matching gate within the relevant IC to aid mapping.

This has also indicated the probable PCB layout, subject to other hardware, so fingers crossed. In the image to the middle are the 4081 Lower and 4001 upper then the 2 4017s on the right. For the rewire one 4017 will be on each side of the logic chips which should aid set up.

In other news. I successfully stripped out the DC wall wart. The transformer has been separated from all extraneous parts. I have had it wired into the mains and tested the output, without regulation as this is what is required, and it outputs 12.8VAC. So the regulators wont be doing much work when the bipolar supply board is built

Well up at 6 this morning to take my youngest to work and as soon as I was back home, cup of tea made, I began wiring the breadboard.

3 1/2 hrs later........ At this point I should point out I cut and trimmed all the wires to aid neatness and ease of fault finding should it come to that... It didn't work.

Luckily I had done the build up fairly logically. All power lines were laid first. Then the 4081 was built up first, its additional components and wire links fittted. The 4001 was done second, it's components and wire links fitted. The 4017s had their reset resistors fitted.

The reset switch and mode switch was fitted and both wired to the correct logic chip. I then routed all the reset enable lines between the logic chips and the 4017s. Not forgetting to route pin 3 of both 4017s via the 4081 and gate for each that helps keep LED 1 OFF on both banks until it is actually wanted.

The bit I missed was 2 link wires that connect the 4081 IC to the 4001 IC Once they were in place things got interesting in a good way

In Mode 1 (1 x 16) leds lit from 1 to 16 and repeat. In Mode 2 (2 x each bank lit from 1 to 8. Initially driven by the same clock but later by separates at different rates a moment or two later.

So it all works as it should

One thing it does need: The reset. When in 2 x 8 the reset does what it says on the tin. it resets to position 1 on both banks. But when in 1 x 16 if the sequence is anywhere in the 2nd bank reset only resets to position 1 in the second bank rather than position 1 in bank 1.

A quicks look at the schem and the addition off an extra diode from the reset switch wired to IC4 pin 4/9 solves this without raising issue elsewhere.

drawn in gimp you said ? you maniac
although it might be working I think you are shorting things a bit with that diode but I can't really tell from the schematic right now.
I love the colors but it's hard to see the signal flow for me so I'd have to redraw it. Anway I think you would have to add some
diodes between pins 10-5 and 4-9 of IC4 too and then you need some pulldown resistors aswell._________________"My perf, it's full of holes!"http://phobos.000space.com/SoundCloudBandCampMixCloudStickney SynthyardsCaptain Collider

Hello there
Cheers PHOBos for your heads up. Here is a schematic based on the addition of more diodes to protect outputs and resistors to prevent floating logic states. Also the wiring is altered to reflect what is on the breadboard. It's all good!

Well I added the extras this morning and after a false start it is all running again. The one change I had to make was to the 2 extra 100K resistors. They had to become 10K, at least I just picked them as my next go to value, to get the default 1 x 16 to run.

Please don't ask me why. I am only a mere amateur. but it's all good!

(Thinks: Are the resistors on the wrong side of the diodes hence the need for value change?)

Now on to the matter of subjectivity. There was one thing, yesterday, that I was not sure of. In 1 x 16 mode the LEDs rolled along and on the roll over it was seamless. But in 2 x 8 mode I was sure I was seeing a slight delay between the last LED going out and the first LED illuminating... Well I just thought it was me.

Now with the changes the roll over is perfect in both modes absolutely seamless Big thanks to PHOBos for pointing out the diodes and the need for the extra resistors to go with them.

I know I had noted there might be a need for these diodes a lot earlier in this thread but in my ignorance I miss read a detail about the outputs being protected internally on CMOS chips so I left them off in the end. So great catch PHOBos and I have learned a little more

So here is a pic of the current schematic as it is on my breadboard (a thing of illuminating beauty).

Going back through my 'papers' here's one I drew earlier. It has the extra diodes in, I posted this image earlier in the thread, I have edited it to add the extra resistors and change the clock input sockets as per a suggestion PHOBos made.

There is a master clock IN on IC1. Which connects to both 4017. But if a second clock is plugged into IC2 then each Clock input is isolated from each other and drives only the IC it is connected to.

Also changed the end out sockets, again as per PHOBos suggestion, to a spur off rather than a switch line. Not sure if I need to fit a resistor in line to preclude any 'drain' issues caused by what ever gets plugged into these sockets at a later date.

ah my idea for the reset was to use them as inputs, so the connections would have to be reversed from the original circuit,
(switch contact on the step switch) didn't notice they were originaly meant as outputs
If you do use them as outputs I would indeed add a (1K) resistor in series as an extra protection.

Ah I see. Well sorted now then . Right I will add 1K resistors in GIMP . Currently I'm spending a lot of time in the kitchen watching the 'pretty lights'. Pressing the mode button randomly in an effort to catch the pixies out and see if it misses a step... o_O

But it's all going great. The weirdest thing as far as corrections against the original PE schematic goes is the lines that go from the last resistor/cap on each 4001 gate at the end. One line from each went to the opposite 4017.

If wired like this what happens in 2 x 8 mode, I think it was, is LED 1 in both banks doesn't light. This may be due to my addition of an additional gate to control LED 1 though changing the dynamic. So now both outputs go to their own 4017 for full function in both modes.

The next thing, other than drawing up the Bipolar PSU, Is to draw up the PCB for the Sequencer. All in one board..... Or stackable multi-board Oh the MADNESS! I'm thinking using header sets as used in arduino boards and shields so 'servicing' can be done in the event of me shoving 12V up the wrong way doing damage :/

Well I've been gradually drawing up some sort of PCB. In fits and starts and mostly tearing it up as it got more complicated than fun!

The core is fine it's adding on the peripheral bits that will interface with the outside world that causes the complications. So I've redrawn the schematic slightly to simplify the 'out'. Hopefully the flow will now happen

Here's a look at the new Schem'

Basically each bank of 8 out puts is completely independent of each other. So they have their own gate/trigger to keep the pulse train working and their own drum trigger output. They did before but there was some crossover dependent on the mode setting.

Now it doesn't matter. The mode only effects what happens at the extreme end of each drum trigger via the 4066 switches.

In 2 x 8 Mode: Start>
One clock or 2 clock doesn't matter. This only means you can run both banks at different speeds or same speed on one clock. Each bank is plugged into it's own drum. the 4066 switches are closed on both banks in this mode.

Heres a quick look at the main PCB. This is unchecked as yet. This holds the pulse train consisting of the CD4081 and Gate2trigger combo. Also a pair of drum triggers. Also the LED drivers.

The theory is the Sequencer core will inter wire to the main PCB the main board then goes out to the panel controls LEDs then back to the drum triggers on the main PCB then out to the Panel for patching out points.

Thats the basic idea. The PCB has a few Power rails missing between sections but it's primarily there at the moment. Though I could still pull the 2 drum triggers of onto their own PCB........

Well its all still going on I've refined the schematic a bit. Basically losing the two AND gates top right. They are not needed as taking the same signal that controls the and gates on on the output 0 of both 4017's switches the 4066 switches. I will post the revised schematic later.

The PCB pattern has changed, it's in flux any way , and I am currently assembling a virtual version in sketchup to see if everything fits as it should.

My only niggle at this point, and it's purely a personal thing, is apart from a few groups I have made separate circuits and then brought them together and the only thing this makes slightly difficult is joining up the power lines.

I should get used to the idea that if it can't be seen and it works stop worrying

I'm now also using GIMP to design the panel layout ,from the back, for a wiring map. This will also be useful as a guide for centres for the front display as I get round to it.

On a slightly different note I have just cloned a Velleman PCB for a 7W amplifier. I have one but on a whim, having the components to hand, am building a second to make a small stereo amp for my workshop (the small worktop allocation in the kitchen). It also is another test of DIY toner etching as I have some .75mm traces on it. I'm gradually getting used to what I can do on screen and if it actually works in real life.

The 170gsm Matt photo paper staples uses for my prints is brilliant. Practically falls off in the water and the toner lays on well no spreading. I think Next time I do a PCB I'll have a swatch of trace thicknesses below 1mm and gaps similarly below 1mm in increments.

Well the refining continues. I have redrawn the Pulse control PCB. This board has the Gate2Trigger circuit, AND gates and the LED drivers on it. In this instance I have broken them back down into 2 pairs.

So a G2T A pair of CD4081 IC and an ULN2308 X2. This has made a more compact and neater board for this part anyway.

I'm eying up the sequencer core to see if I can improve it further and address the power routing. Here's a pic of the PCB in question and the revised Schematic with the previously mentioned AND gates removed.

Fen

PS. The 7W Stereo Amp works great. Just Knocking up a wooden case for it to hone my enclosure skills back up to snuff

Now the Pulse board seems sorted I am revisiting the sequencer core. At this juncture I've just relaid the MFOS drum trigger circuit out again. This time I think I got it down neat compact and fairly ordered in as much as where inputs outputs and power all are. Also with a deft bit of mirroring I have Two identical twins except for where you have to watch not to flip the IC with respect for the power pins. Other than that All the other pins mirror perfectly.

This does mean I may have to revisit the 4017 sections and possibly the logic core once more But it keeps me off the streets on these dark autumn nights......

Any way a pic. You may notice that the trigger circuits top/bottom right have the text reversed. The circuit is correct I just haven't adjusted the notation yet.

Well here's a look at the 2 PCB's. I believe, subject to checking, that everything is correct. Both are 98mm X 80mm One is the Logic Board which also has the 4017 and drum trigger circuits on. The other is the Pulse driver board and LED display.

14 Chips in total to drive either one drum module, in 1 x 16 mode or 2 drum modules in 2 x 8 mode. I hope this is going to be worth it! Especially as the intention is to build multiple units.

Well stuff has been ordered to get on with the build. Sadly I realised a little late I'd neglected to order the 3.5mm stereo sockets needed to interface I/O. but there ya go

In the mean time I keep fettling the PCB layouts slightly. I'm pretty happy with the result. Both boards have a good power route to all parts now and I'm pretty sure everything is correct....... Subjct to further checking

Also been playing in GIMP with panel layouts. One for the wiring and one for the front view. These are done as if there are the full 5 sequencer circuits, as planned, rather than just the one that there will be for now.

In the throes of all this it looks like the way this is being done may change. I was aiming at an all in one unit. Sequencer, Drum circuits, Clocks and Clock variants. As it stands this unit may change to 'Sequencer and Clock/Clock Variants'. We shall see how it goes.

Also nearly finished my mini amplifier Outstanding is a pair of small brackets to tie the heat sink to the metal back panel for stability and something to 'fill the access hole' with. I was going to make a wood tray for my MP3 player to lay in. But I think a better solution is to enlarge the hole and line it with an ABS form keeping a more low profile finish. The first blue LED died! Checking the 12V DC PSU it is actually putting out just short of 16V DC! So new LED and a 1.5K resistor and it's all good.

The extra volts also mean I am getting around 7W output So all that and a bit of paint and the jobs a good'un.

Not much to report. Other than my parts have arrived..... I have been allowed to check them off.... But I'm not allowed them until christmas!

That said I can wait. It's not far off and I have the PSU to draw up as well...... Though the 2 regulator chips are in the same order as well...... DAMN!

Looks like apart from forgetting to order the audio sockets the other fly in the ointment turns out to be the LEDs I ordered. Not sure what I thought I was ordering but it seems it's a mixed bag of LEDs so other than useful for random projects, not what I wanted for this....... DOH!

My idea was to possibly have each sequencer colour coordinated. So red LED's with knobs that have a matching marker. Green LED's.... etc etc.

In other news. I've been absent a few days due to being a tad unwell. Not drinking enough fluid on my new anti migraine medication, bad mistake! Missed some good radio streaming as well by the looks of it but things are on the mend now. Once I began rallying I managed to play around and breadboard a nice colour organ circuit I found online. 2 of these, for stereo, will be built and fitted in my mini amp.

Also turns out I have a load of TL074 TL072 IC's so I'm going to knock up some drum trigger boards for testing purposes

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